Improvement in the manufacture of carbonate of



` immonet/:ENT ne 'ran MANUFCTURE To all whom 'it 'ma/y concern :j

`of its capacity in a horizontal direction.

"f, IsIDoR'WLZANDJOHN PENDLETON., or NEW YORK, N. Y;

` i Letters PatentNo. 90,140, dated May 178, 1869.'

or'l cARBoNA-rn orsonA AND OTHER erremcALs.

The Schedule referred to in these Letters Patent and making part of the same,

Be it known that waismo Witz land JOHN M.

PENDLETON, both of the city and county of New York,

State of New York,`have invented a newand useful Method for the Manufacture of Carbonate of Soda and f fother Chemicals; and we do hereby declare that the following is a full and exact description thereof.

We will irst'describe what We consider the best Vmeans of lcarrying out our invention, and will afterwards designate the points whichwe believe to be new therein. i

-Wetake carbonate `of lime, either as obtained artificially or as it occurs in nature, and nitrate of soda, either as artificially prepared, or as it occurs in nature,

` both preferablyin a dry, pure, and pulvernlent condition, and mix well togethenlin the proportion of seventeen parts of nitrateof soda toten parts of carbonate of lime, or in such'larger proportions of carbonate of `lime as may be deemed expedent, and fill a cylindri-Y cal retort to from one-third part to threefourths parts This retort is thenplaced in a'furnace, constructed mainly like the furnaces used for heating the retcrts in the, manuf facture of illuminating-gas. Atits rear end each retort', terminates in a tube which passes through and i projects beyond the rear wall of the furnace. The

front endof suchy retort rests in the front wall of4 the i furnace, so that the retort shall have a horizontalpositioc. u y `which may, attwill, betaken therefrom or connected*V Each retort should be provided with a cover,

therewith firmly and tightly. Such cover has an openngforv the introduction `of a pipe, which' serves `the purpose of"introducing steam into the retort. -.It extends from `the front `of the retort `to` withinv a few inches ,of its rear eud,'andiis provided with one or c morenopenings suitably disposed within the retort.

`W'e thencounect that part vof this pipe, which projects beyond ,the retort in front by a proper coupling,l

` `with'an iron tube connecting witha steam-boiler, and `provided with proper cocks, valves, orother contrivances for admitting, regulating, or shutting Voii' the"` steam. We connect the rear end of the tube which projects; beyond the rear wallof the furnace, by proper joints and couplings with-a series of large stone-warexireceptacles, known `as Woulfesj bottles, which shall contain 'a larger or smaller amount of water.` The furnace contains from one to ive retorts,`pipes, covers, tubes, and connections, as above described. We

then heat'the furnacewith coal o1" coke, or other car'- bonaceous material, so that-the retortsand their contents shall attain a temperature from dark lto bright red. We at the same time ad'mit steam iuto'the re-` torty by meansofthe appliances above described. At

" such temperature the chemical andphysical changes,

- combinations, and decompositions taking place in the retort may be expressed by the following chemical for mula:` OaOCO,+N aON O,-.1-HO=GaO l;NaOOO2-|N 05,110, which may be interpreted asifollowsr First, the nitrate of soda is decomposed into anhy-` dFOuS oxide of sodium on the one hand, and nitric acid o n the other hand;

Second, the nitric acid is decomposedby the heat i into oxygen and combinations of nitrogen, with less i oxygen than is contained in nitric acid.

Third, the carbonate of lime is decomposed into auhydrous oxide of calcium (or quick-lime) `on the one hand, andcarbouic acid on the other hand. i

Fourth, thefauhydrous oxide of sodium' (or caustic soda)I unites chemically `with the vcarbonio acid, and formsmaiuly, or altogether, carbonate of soda.

Eifth,the steam introduced into the retort becomes superheated iu contact with'the heated mass and the heated sides of the ret`ort.

Sixth, this superheated steam reunites the oxygen Y.

with the lower combinations of nitrogen and oxygen,

s as tovregenerate nitric acid, and unites therewith f to form a gaseous solution of this acid.'

The iinal, products of this process are-4 First, agaseous solution of nitric and hyponitrc acids in steam. This is carried through the tube formv Y ing the 'rear end y,of the retort into the` above-mentioned series of Woulfes bottles, and condensed-therein, forming more or less concentrated solutions of nitric i and nitrous acids. These solutions are distilled and concentrated together, or separately, according to the methods in existence for this purpose, so as to produce Vmore or less concentrated solutions of commercial or v pure nitric acid. y A

Second, a siutered or melted mass, consisting of quick-lime and carbonate of soda, and possibly of some caustic soda. The re is extinguished, the retorts al lowed to cochand this mass taken out and suitably broken np.

` (A.) This mass may now be brought directly into the market, and may be used to produce solutions of .caustic soda by -dividiug it into small fragments, and; -placng them in vats, tubs, or other receptacles, with sufficient water, which may be heated byv steam, or directly by fire, when the following change will take place:

NaOCOz-l-OaO+HO=GaOGO2+NaOHO thatv is to say, the water will dissolve the carbonate of soda, and

leavethe lime undissolved. The higher temperature will aid this dissolving-process, and cause the forma,-

tion of carbonate of lime and a solution of caustic (B.) Or by another method of4 operating, we take this mass, suitably comminuted, and place the same yin ya vat with a sutcieut quantity of water to dissolve all the'carbonate of soda. The process of dissolving' may be aided and accelerated by stirring or otherwise v agitating the contents of said receptacle.

is allowed to settle and the supernatant liquid, which forms amore or less concentrated solution of carbonate of soda, drawn off and concentrated, evaporated or crystallized, according to the usual methods employed for this purpose.

(C.) Or, again, if` preferred, we can take this mass suitably `comminuted. and place the same with water- The lime (sufficient to dissolve all of the carbonate of soda present) in a vat which must be provided with appliances for raising the temperature. We then raise the temperature to the boiling-point when the following chemical change will take place: NaOC-Oz-l-CaO-I-HG--Na OHO-{eGaOCOm which may be interpreted as follows:

Carbonate of lime is formed which is insoluble in the supernatant liquid, and sinks to the bottom, and a more or less concentrated solution of caustic soda is formed, which is drawn oli', concentrated, evaporated, and reduced to a dry state by the' usual methods employed for that purpose.

The carbonate of lime formed is dried, and may be employed to form a fresh mixture with nitrate of soda, as above described.

We can use in our process carbonate of lime in the form of limestone, marble, calcspar, or any other mineral containing lime and carbonio acid in a dry or moist, pure or impure, crystalline or amorphous, or pulvcrnlent condition, and nitrate of soda in the form of Chili nitre, or Chili saltpetre, or soda saltpetre, or any other mineral (by whatever name it may be known,) containingsoda and nitric acid in a dry or moist, pure or inlpure, crystalline or amorphous, solid or pulverulent condition; but we prefer both in a dry and finely-divided condition, as above stated.

We can use all ordinary materials for the vats or tubs for the final treatment, and heat by any convenient means; but we prefer hard wood for the vessels and heating by steam-pipes when plenty of steam can be conveniently commanded.

' ments.

The accompanying drawings represent the apparatus we employ to carry out our invention.

Figure 1 is a front view, and

Figure 2, a vertical section of the apparatus.

We are aware that Karl Lieber has, in his patent dated December 15, 1868, described certain fimprove Such we do not claim. Neither do We claim as new anything in the above connected with the form, material, or arrangement of the various furnaces, retorts, vats, tubs, or other receptacles and Woulfes bottles, or anything connected with the working up the first, solutions of nitric acid as condensed in the Wonlfes bottles, or with the working up of the mass, consisting of quick-lime and carbonate of soda, into a marketable state; but

We claim, in the process of manufacture above described- 1. The use of steam in connection with a heated mass of carbonateof lime and nitrate of soda in a highly-heated vessel or retort for the regeneration of nitric acid, substantially as above described.

2. The production of a mass, consisting'of quicklime and carbonate of soda, in exactly or nearly their chemical proportions or equivalents, and forming a mass Yapplicable to the production of caustic-soda lyes from carbonate of lime and nitrate of soda, treated in the manner substantially as herein described.

` ISIDOR WALZ.

Witnesses: JOHN M. PENDLETON.

J. R. STURGEs, yO. S. CLARK. 

